The introduction of self-service to the gasoline marketing segment of the oil industry, as a cost-saving factor, has been accelerated by recent oil shortages. One problem that has slowed its use, however, is the cost of new equipment heretofore thought necessary to provide for self-service operation.
Essentially self-service operation requires a means for monitoring each dispensing cycle of the gasoline pump to assure that a dispensing operation cannot be started without interposition of some signal to the equipment. Such a signal can be provided by insertion and turning of a key-operated switch or by otherwise actuating a manual switch either at the gasoline dispensing device or at a remote console where several pumps or dispensing devices are being monitored.
The concept of the present invention is to provide an apparatus for converting or modifying existing gasoline pumping or dispensing devices to provide self-service operation. The apparatus consists of two electromagnetic relays, a key-operated switch and a relay lamp. These are interconnected so that they may be interposed in the conventional reset circuit of the gasoline pump or dispensing apparatus. Only a minimum number of adapting connections need be made to the pump reset circuit and these are substantially the same for both remote submerged pump installations and self-contained units.